Does vitamin D offer benefits beyond bone health?

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Researchers continue to report on a growing body of evidence that indicates vitamin D plays a much larger role in regulating health than simply helping build strong bones. Vitamin D appears to help regulate cell growth, immunity, musculoskeletal health and various other biological functions that play a role in keeping us healthy.1,2,3 Scientists are currently working to better understand all the benefits that vitamin D has to offer. 4,5† Read on to learn more about dietary recommendations for vitamin D, current dietary intakes and ways to improve your vitamin D status.

Dietary recommendations for vitamin D

Researchers have yet to agree on the amount of vitamin D needed for optimal health. However, experts at the National Academy of Sciences recently established a new set of dietary recommendations for vitamin D, including Adequate Intake (AI) levels that serve as a goal for the nutrient intake of individuals. The AI levels for vitamin D are:

Children and adults up to age 50: 200 IU per day
 Adults 51-70 years: 400 IU per day
Adults above 70 years: 600 IU per day

The Tolerable Upper Intake Levels (ULs) for vitamin D are set at 2,000 IU per day for children and adults, which is the maximum level of daily nutrient intake that is likely to pose no risk of adverse effects. The UL represents total intake from food, water and supplements.

Current dietary intake of vitamin D

Some researchers have reported that vitamin D intake is often too low to sustain healthy circulating levels of the active form of this nutrient. This is mostly due to unique dietary patterns, such as low milk consumption, vegetarian diet, limited use of dietary supplements or low fish intake.6

Furthermore, nutrition surveys suggest that the majority of Americans fail to consume enough vitamin D from food sources and dietary supplements combined. Based on these findings, some researchers have proposed that additional food fortification as well as dietary and supplement guidance are needed for the general population.7

Ways to improve your vitamin D intake

Vitamin D is obtained from two sources: sunlight and diet. The skin manufactures the majority of the body's vitamin D after direct exposure to sunlight, but as adults age the ability to make vitamin D through the skin diminishes. Avoiding sun exposure or using sunscreen can also limit a person's production of vitamin D. Good dietary sources include salmon and other fatty fish, shrimp, and vitamin D fortified foods such as milk, orange juice and cereals. However, for many people, dietary sources alone may not be enough.

Until public health officials make further recommendations, some researchers advise regular sun exposure, consumption of foods rich in vitamin D and a daily vitamin D supplement. Others propose that, in the absence of adequate sun exposure, 1,000 IU of vitamin D per day for children and adults is required to achieve adequate circulating levels of the active form of vitamin D.4 †

Adequate sun exposure is 4-10 minutes for people with pale skin in the summer noonday sun in the southern United States; for African Americans and others with darker skin tones, the corresponding time is 60-80 minutes.4 Since the length of time for sun exposure varies with geographical location, skin pigmentation, percent body fat and age, careful attention to obtaining dietary sources of vitamin D and daily supplementation is prudent.

References

  1. Raiten DJ, Picciano MF. Vitamin D and health in the 21st century: bone and beyond. Executive summary. Am J Clin Nutr. 2004;80:1673S-1677S. PMID: 15585787
  2. Cantorna MT, Zhu Y, Froicu M, Wittke A Vitamin D status, 1,25-dihydroxyvitamin D3, and the immune system. Am J Clin Nutr. 2004;80:1717S-1720S. PMID: 15585793
  3. Montero-Odasso M, Duque G. Vitamin D in the aging musculoskeletal system: an authentic strength preserving hormone. Mol Aspects Med. 2005;26:203-319. PMID: 15811435
  4. Grant WB, Holick MF Benefits and requirements of vitamin D for optimal health: a review. Altern Med Rev. 2005;10:94-111. PMID: 15989379
  5. Holick MF. Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis. Am J Clin Nutr. 2004;79:362-371. PMID: 15585788
  6. Calvo MS, Whiting SJ, Barton CN. Vitamin D intake: a global perspective of current status. J Nutr. 2005;135:310-316. PMID: 15671233
  7. Moore C, Murphy MM, Keast DR, Holick MF. Vitamin D intake in the United States. J Am Diet Assoc. 2004;104:980-983. PMID: 15175600

† These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.